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Single Piece Flow: The #1 Lean and Agile Tool

The Lean Product Development Toolkit is the basis of all Lean and Agile Project Management today. It includes the habit of working in Single Piece Flow (one project at a time), working in a One Room (or Obeya) Environment, to have one Chief Engineer responsible for the entire project, to engage in Concurrent Engineering and to use the typical A3 Problem Solving method for continuous improvement.

One of the most important principles in Lean is the principle of Single Piece Flow: To finish building one product before starting to build the next. In a production environment this principle leads to the elimination of batches. When we eliminate batches, we complete a product sooner. A classical example shows the assembly of computers: Make a screen, make a computer and connect it to the screen, test it. Suppose that making a screen takes three minutes, and making a computer and connecting it to the screen takes three minutes, and that testing the sets also takes three minutes.

Working in batches, means that we first make 10 screens, then we make 10 computers and connect them to the screens and finally we test 10 sets. It would take 30 minutes for the batch to be moved from the first step (of making the screen) to the second step (making the computer and connecting it to the screen), and another 30 minutes to move to the testing steps –plus an additional 30 minutes to be completed-: All in all, it takes 90 minutes for the customer to have his computer. Suppose now that the fourth of the units is not working properly. We would find out about that only after 60 minutes + 4 x 3 minutes = 72 minutes.
Working in Single Piece Flow on the other hand, means that we would make one screen, one computer, connect the two and test the set in one blow. It would take us only 9 minutes (3 + 3 + 3 minutes) to deliver the first set to a customer. We would know about the failure in the production of the fourth set after 33 minutes only. More importantly, we would be able to solve the problem causing the defect, before completing all the other sets -which may come to suffer from the same defects-.

Batches of 10

Single Piece Flow

First set delivered after

63 minutes

9 minutes

Defect in 4th set discovered after

72 minutes

33 minutes

These are only two reasons why in Lean we generally prefer to work in Single Piece Flow: It allows to deliver sooner and to improve our method when we need to. In fact, evidence has shown that lead times per item increase exponentially to the amount of work in progress. This is another way of phrasing our reasons for reducing the amount of work in progress.

Comparably, when Toyota decided it had to speed up it’s product development process, in order to accommodate workers who were freed up by Lean efforts in existing production lines, their first measure was to reduce the amount of projects being executed simultaneously. They decided to have dedicated teams working in single piece flow, working on one model only until finished. That way, they were able to reduce the time to market for a new model from 3 years to 9 months.

Most project organizations today don’t apply this same principle. Time and again we find companies running tens or even hundreds of projects simultaneously. Individual team members, often specialists, are not dedicated to one project only, they are added to several project teams at a time. They need to keep up with data on many different problems, they need to join meetings on many different issues, meet with different people… Each time they want to go to work on one project, their attention may be grabbed by another project. If other team members are waiting for their contribution, they too will shift their attention to something else, further aggravating the problem. The root cause for all this is that individuals are not dedicated to one project only.
In Waypoint we still allow you to work on multiple projects. After all, that’s most companies’ reality today. And it will take time and effort to move to Single Piece Flow mode. But Lean and Agile Project Management do propose you to change that. And to build a pipeline with all your projects and to complete them preferably one by one. That’s a lot more efficient than working on many projects simultaneously. It’s often not easy to organize, but it can be done, in almost all project environments. Doing that, will allow you to focus your energy on the completion of projects. It will reduce the cost of each project and probably improve the quality too. Last: It’s much more fun and energizing for people to work on something and then to complete it too.

Waypoint is project management software to support the execution of Lean and Agile projects, in software development, new product development, construction, Waypoint is software to support lean project leaders and teams. The software allows to budget, plan, report, standardize and improve project execution, along the principles of Lean Project Management and Agile Programming and Planning. Waypoint is offered by Heyunka, a provider of on-line tools for the implementation of lean management and agile development.Heyunka's tools are web-based and require standard compliant browser. Clients are charged only for actual usage -from one to as many users as you like and for as long as you need it. Tools are sold on-line. No IT needed.